As illustrated in FIG. 6, a known motor drive device (refer to PTL 1, for example) includes a first motor driving unit 110 that functions as a converter, and a second motor driving unit 120 that functions as an inverter. The first motor driving unit 110 and the second motor driving unit 120 are connected with each other through a pair of short bars 130.
A known connection member includes a bus bar of one side including two elongated plate members disposed with an interval therebetween in the thickness direction, a bus bar of the other side which is formed in an elongated plate shape and which is inserted between the two plate members of the bus bar of the one side, and a long hole formed in the bus bar of the other side and extending in a longitudinal direction thereof, and a bolt inserted into the long hole of the bus bar of the other side through the two plate members of the one bus bar in the thickness direction (refer to PTL 2, for example). When the bolt is loosened in this connection member, the bus bar of the other side can be moved relative to the bus bar of the other side in the longitudinal direction to adjust the length of the connection member.
In a known plate bus bar having one end that is connected with a terminal block of an inverter circuit and the other end that is connected with a terminal block of a motor or an electric generator, a plurality of grooves extending in a direction orthogonal to the longitudinal direction of the bus bar are provided at a central part of the bus bar in the longitudinal direction to improve the bending flexibility in the thickness direction and heat-releasing performance when the bus bar has a large plate thickness (refer to PTL 3, for example).
When this bus bar is used, a stud bolt provided on the terminal block of the inverter circuit is inserted into a through-hole provided in the one end of the bus bar, and another stud bolt provided on the terminal block of the motor or the electric generator is inserted into a through-hole provided in the other end of the bus bar. Then, the stud bolts are screwed with nuts to fix the ends of the bus bar. Since the central part of the bus bar is easy to bend because of the grooves, one end of the bus bar can be removed from the corresponding stud bolt by bending the bus bar in the thickness direction at the central part after removing the nut of the stud bolt while the other stud bolt is screwed with the nut.